Converts butterflies to basic mobs and adds them to cytology (#75582)

## About The Pull Request

Converts butterflies into basic mobs.
Also a little list organisation.

<details>
<summary>Yep, those are some butterflies alright</summary>


![image](https://github.com/Skyrat-SS13/Skyrat-tg/assets/8881105/d9e3a14e-e0a5-4275-b440-af0a56e7b8fe)

</details>

## Changelog
🆑
refactor: Converted butterflies to the basic mob system
add: Butterflies can now be grown in cytology
/🆑

code/datums/diseases/anxiety.dm

@@ -40,5 +40,5 @@
 			if(SPT_PROB(1, seconds_per_tick))
 				affected_mob.visible_message(span_danger("[affected_mob] coughs up butterflies!"), \
 													span_userdanger("You cough up butterflies!"))
-				new /mob/living/simple_animal/butterfly(affected_mob.loc)
-				new /mob/living/simple_animal/butterfly(affected_mob.loc)
+				new /mob/living/basic/butterfly(affected_mob.loc)
+				new /mob/living/basic/butterfly(affected_mob.loc)

code/datums/memory/_memory.dm

@@ -245,6 +245,7 @@
 
 	var/static/list/something_pool = list(
 		/mob/living/basic/bat,
+		/mob/living/basic/butterfly,
 		/mob/living/basic/carp,
 		/mob/living/basic/carp/magic,
 		/mob/living/basic/carp/magic/chaos,
@@ -261,7 +262,6 @@
 		/mob/living/basic/statue,
 		/mob/living/basic/stickman,
 		/mob/living/basic/stickman/dog,
-		/mob/living/simple_animal/butterfly,
 		/mob/living/simple_animal/chick,
 		/mob/living/simple_animal/chicken,
 		/mob/living/simple_animal/crab,